Michael "Mikey" Musumeci began his Brazilian Jiu-Jitsu journey at age four under coach Fernando "Cabeça" at Fatijo’s Martial Arts Academy. Demonstrating exceptional dedication and rapid technical progress from the outset, Mikey quickly established himself as a promising young talent. At age 10, his family relocated to Wellington, Florida, where he briefly trained at Marcelo Ribeiro’s gym before joining American Top Team under coach Emyr "Shark" Bussade, who awarded him his green and blue belts.

Musumeci's competitive success began early, earning his purple belt from Javill Byron at WMB Miami after capturing his second juvenile world title as a blue belt. His technical development was significantly influenced by his relationship with the renowned Mendes brothers, Rafael Mendes and Guilherme Mendes. Guilherme Mendes notably awarded Mikey his brown belt on the podium following his victory at the 2014 IBJJF World Championship. At just 18 years old, after winning the 2015 IBJJF World Championship at brown belt, Mikey received his black belt from coaches Jonatas Gurgel and Gilbert Burns. Throughout his career, he has also extensively trained under Caio Terra and Heath Pedigo.

In late 2024, Mikey Musumeci made history by signing the first-ever exclusive grappling contract with the UFC. He headlined the UFC Fight Pass Invitational 9, marking a groundbreaking moment as the first Brazilian Jiu-Jitsu athlete signed solely for grappling competition in UFC history. Prior to this landmark achievement, Mikey had already established himself as a dominant force in ONE Championship, capturing multiple titles and showcasing his crossover appeal.

Though primarily recognized for his grappling expertise, Mikey has actively pursued MMA cross-training. In 2023, he traveled to Thailand to train Muay Thai under legendary fighters Nong-O and Rodtang, aiming to achieve striking proficiency comparable to a blue or purple belt level. Mikey has openly expressed interest in eventually competing in MMA, signaling a potential future transition alongside his grappling career.

At ONE Fight Night 15 in October 2023, Mikey Musumeci showcased remarkable resilience by overcoming severe food poisoning and challenging hydration weigh-ins. Despite these adversities, he secured a memorable victory against Japanese legend Shinya Aoki, submitting Aoki with his own signature leg lock. Mikey described this victory as one of his proudest moments, symbolizing a significant "passing of the torch" between generations.

After years in structured team environments, Mikey adopted an independent training philosophy. He frequently splits his training between various gyms, including Evolve MMA in Singapore and local academies in Las Vegas. Known for meticulous self-study and innovative drilling methods, Mikey often trains solo or collaborates closely with his sister, Tammi Musumeci. This self-driven approach underscores his reputation as one of Brazilian Jiu-Jitsu’s most analytical and innovative minds.

Mikey Musumeci is renowned for his highly technical and innovative guard play, emphasizing submission-oriented strategies. His meticulous approach involves detailed positional study and strategic preparation tailored specifically for elite competition. Additionally, Mikey publicly advocates for ecological and sustainable training methods within the broader Brazilian Jiu-Jitsu community, promoting longevity and effectiveness in training practices.

Mikey famously embraces the nickname "Darth Rigatoni," a playful nod to his Italian heritage and unique dietary habits. He consumes one large, carbohydrate-rich meal daily—typically pizza or pasta—after training sessions, while fasting throughout the day on water, electrolytes, and caffeine. Despite its unconventional nature, Mikey credits this diet with enhancing his happiness, athletic performance, and exceptional physical conditioning.

Mikey Musumeci has been vocal about his concerns regarding performance-enhancing drug (PED) use within Brazilian Jiu-Jitsu, particularly among younger athletes. He publicly criticizes the culture of PED use in competitive BJJ, specifically mentioning prominent figures such as Gordon Ryan. Mikey continues to advocate for clean competition, transparency, and integrity within the sport, emphasizing the importance of fair play and athlete health.